The Original Un-DatabaseThe V part of the name stands for
"Virtual", which simulates a list of records sequenced by their Keys.
The SAM part stands for an age old data storage technique ISAM (Indexed
Sequential Access Method) used to store very large datasets on main frame computers
in the past. Extremely fast binary and tree search methods can find any record in
the dataset in microseconds.

The ISAM method was originally developed by IBM in order to process large
amounts of data in an organized and speedy way. Even today, it remains one of
the most generic, fundamental tools for all data base developers. It is found
at the core of many relational databases. There have been many implementations
and improvements to the original IBM design over the years and the VsamEx[treme]
ISAM is one of the best!

Simple API - Easy to useVsamEx[treme] has been designed from the ground up to enable
application developers to easily incorporate data
management into their applications! There are no complex tables
to join or merge into 3rd normal form! The essential
concept is one of a record. Each record is
named with a label called a KEY (1 - 252 characters)
-
much like a disk file has a "file name". A record
consists of all of the fields for which information
has been supplied and previously saved by the application.
The essential operations are READ a record and
WRITE a record. There are extensions that provide
a robust programming tool such as OPEN, CLOSE, SetBOF,
SetEOF, etc. but, these support the fundamental concept
of read and write.

Example

Lightning Fast
Because VsamEx[treme] restores data management to the application at
the lowest level, it is Inherently lightning fast.
The VsamEx[treme] ISAM gives the programmer a
lot of flexibility in organizing all kinds of tables and ad hoc information.
Records in a VsamEx[treme] ISAM dataset are indexed using variable
length keys
(labels) of up to 252 characters. This means that the programmer can get to any
data item instantly by any key, usually in microseconds. At any point, data may
be retrieved sequentially from the current spot, either forward or backward in
direction. Data is maintained alphanumerically (kind of like a Rolodex file).
Since the VsamEx[treme] ISAM is totally consistent, as records are added
and removed it reacts as you would normally expect in the real world - there is
no guessing about where the data went or how to get it back! On modern PC's,
query functions allow for complex full text Boolean searches at over 5 MB per
second. Fully indexed Dynasets may be created from the resulting queries.

Multiple User Access
In addition to VsamEx[treme] being an ISAM, it also supports
multiple simultaneous access by many users (multi user), all of whom may be
actively retrieving or updating the dataset. While VsamEx[treme] supports
data sharing through the Microsoft "Shared
file" model, the
Client/Server shell ( Vservice) will cut network loading and improve
network access by several orders of magnitude. It will run on any Windows computer,
not just a Microsoft server. There are no "Opportunistic
Locking" bottlenecks to consider. The
Vservice model virtually eliminates
the tremendous overhead imposed by the Microsoft shared file model, not to mention
the expense required to support a full Microsoft server. VsamEx[treme] ISAMis a
royalty free product that runs on any network supporting binary data files.
It's small (about 170k of executing code), supports full "Record
Locking", is easy to use and as reliable
as an anvil. This makes it attractive for
those programmers who find other larger data access engines too slow, too big,
too complex or too unreliable to create stable end-user products.

The VsamEx[treme] ISAM is perfect for CD-ROM Publishing and network
distribution, it is truly Industrial Strength!

Software Source also provides the best product support you can find. We
actually answer the phone and return your calls the old fashion way - in person!
-- No phone-tree support! -- If you need consulting, including product, or
design assistance, we provide that as well!